Hi Benjamin, There may be faster ways, but v <- 1:100 x <- 10 n <- which(cumsum(v) == x) w <- v[1:n]
seems pretty straightforward. Best, Ista On Wed, Mar 2, 2011 at 10:42 AM, Benjamin Hartley <benhartley...@googlemail.com> wrote: > I have a question regarding the most efficient way to select a substring of > a vector: > > I have a vector of value v, and I want to select a subspace of this vector > called w such that: > > w=v[1:n] > > where > > sum(w) = x > > I am interested in what you thing would be the most efficient way to do this > - I would like to avoid slowing down my simulations as much as possible. > > Thank you very much for any help that anyone is able to give. > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Ista Zahn Graduate student University of Rochester Department of Clinical and Social Psychology http://yourpsyche.org ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
